Energy Flashcards
Electrophysical agent
- Form of therapy used in rehab that produces a change in soft tissue through light, water, temp, sound, or electricity
- these include transcutaneous electrical nerve stim (TENS), ultrasound, whirlpool, hot and cold packs, and other modalities
- application and removal of energy from biological tissue in order to stimulate that tissue to perform its normal function
Energy
- The capacity of a system for doing work or its equivalent in the strict physical sense
- energy is manifested in various forms: motion (kinetic), potential, light, heat, ionizing radiation, and sound
- neither created nor destroyed
Radient energy
- Process by which energy of various forms travels through space
- all substances with temps above absolute zero (-273 degrees Celcius) emit radiant energy
- occurs when sufficient electrical or chemical force is applied to an object
- explained by combo of 2 theories
- quantum theory
- electromagnetic wave theory
- thought of as a packet or particles of energy carried along by propagating waves
- constant velocity
- radio waves, microwaves, infrared waves, visible light waves, ultraviolet waves, x-rays, gamma rays, and cosmic rays
Quantum theory
- pocket of energy-photon
- produced by high velocity electronic or molecular motion or transformed kinetic energy released when molecules collide
- E (quantum)= H (planck’s constant) X f (frequency)
- the higher the frequency the higher the photon energy> potentially destructive
Electromagnetic wave theory
- Energy is tranmitted by oscillatory motion i the form of electromagnetic waves
- composed of electric and magnetic fields that vary over time and are oriented perpendicular to each other> electromagnetic wave
- can propagate without the need of a medium (travel through vacuum)
- velocity= wavelength X frequency
- the shorter the wavelength the higher the frequency
radient energy: frequency vs energy
- quantum theory states if frequency is low, energy must be low
- electromagnetic theory states if frequency is low then wavelength is long (high)
- so, therapeutic modalities at low electromagnetic frequencies have relatively long wavelengths and low amounts of energy , and are safe to apply to human system
radient energy: lower frequency electromagnetic radiation
- ELF waves, short waves, microwaves, IR radiation, visible light, and Ultraviolet A & B radiation
- nonionizing: can inhibit cell division, break molecular bones and form ions
- potentially destructive
Laws governing effects of electromagnetic radiation
- Arndt-Schultz
- law of Grotthus-Draper
- cosine law
- inverse square law
- Bunsen Roscoe law of reciprocity
Arndt-Schultz principle
The energy absorbed must be sufficient so as to stimulate the absorbing tissues
- too much energy absorbed may impair normal function to tissues
- Examples
- E-stim for muscle contraction, current intensity must be strong enough to cause depolarization of the nerve
- Heat to increase tissue elongation. must be intense enough to increase viscoelastic properties of tissue
Law of Grotthus-Draper
If energy is not absorbed by the superficial tissue then it will penetrate to deeper tissues
* ex 1MHz US will be more efficient in treating deeper tissues than 3 MHz US
Cosine law
- the max amount of absorption of radiant energy occurs when the source is at right angles to the absorbing surface
- energy absorbed= energy available X cos
- more perpendicular to absorbing tissue= more energy absorbed
inverse square law
the intensity of radiation striking the surface varies inversely with the square of the distance from the source
- move further away and intensity drops by a square of the distance
Bunsen Roscoe law of reciprocity
- The intensity and duration of the dose of radiant energy are inversely proportional
- Energy (E)= intensity (I) X time (T)
How do the laws work?`
To increase the amount of energy absorbed by the pt (dosage):
- inc treatment time
- inc treatment intensity
- lessen the distance of the source of energy to the pt
- make the source of energy more perpendicular to the absorbing surface
Electromagnetic modalities
- E-stim
- biofeedback
- iontopphoresis
- short wave and microwave diathermy
- infrared
- UV
- low power laser